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common/iobuf.c: When requested, fill the buffer even if it is not empty. 

* common/iobuf.c (underflow): Don't require that the buffer be empty.
When called, fill any available space.

--
Signed-off-by: Neal H. Walfield <neal@g10code.com>.
This commit is contained in:
Neal H. Walfield 2015-08-12 22:10:37 +02:00
parent e76c75d872
commit c7ad36eb0d
1 changed files with 92 additions and 46 deletions
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138
common/iobuf.c
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@ -1767,18 +1767,38 @@ underflow (iobuf_t a)
size_t len;
int rc;
assert (a->d.start == a->d.len);
if (a->use == IOBUF_TEMP)
return -1; /* EOF because a temp buffer can't do an underflow */
if (DBG_IOBUF)
log_debug ("iobuf-%d.%d: underflow: buffer size: %d; still buffered: %d => space for %d bytes\n",
a->no, a->subno,
(int) a->d.size, (int) (a->d.len - a->d.start),
(int) (a->d.size - (a->d.len - a->d.start)));
if (a->filter_eof)
assert (a->use == IOBUF_INPUT);
/* If there is still some buffered data, then move it to the start
of the buffer and try to fill the end of the buffer. (This is
useful if we are called from iobuf_peek().) */
assert (a->d.start <= a->d.len);
a->d.len -= a->d.start;
memmove (a->d.buf, &a->d.buf[a->d.start], a->d.len);
a->d.start = 0;
if (a->d.len == 0 && a->filter_eof)
/* The last time we tried to read from this filter, we got an EOF.
We couldn't return the EOF, because there was buffered data.
Since there is no longer any buffered data, return the
error. */
{
if (DBG_IOBUF)
log_debug ("iobuf-%d.%d: underflow: eof (pending eof)\n",
a->no, a->subno);
if (a->chain)
/* A filter follows this one. Free this filter. */
{
iobuf_t b = a->chain;
if (DBG_IOBUF)
log_debug ("iobuf-%d.%d: pop '%s' in underflow\n",
a->no, a->subno, iobuf_desc (a));
log_debug ("iobuf-%d.%d: filter popped (pending EOF returned)\n",
a->no, a->subno);
xfree (a->d.buf);
xfree (a->real_fname);
memcpy (a, b, sizeof *a);
@ -1787,82 +1807,108 @@ underflow (iobuf_t a)
}
else
a->filter_eof = 0; /* for the top level filter */
if (DBG_IOBUF)
log_debug ("iobuf-%d.%d: underflow: eof (due to filter eof)\n",
a->no, a->subno);
return -1; /* return one(!) EOF */
}
if (a->error)
if (a->d.len == 0 && a->error)
/* The last time we tried to read from this filter, we got an
error. We couldn't return the error, because there was
buffered data. Since there is no longer any buffered data,
return the error. */
{
if (DBG_IOBUF)
log_debug ("iobuf-%d.%d: error\n", a->no, a->subno);
log_debug ("iobuf-%d.%d: pending error (%s) returned\n",
a->no, a->subno, gpg_strerror (a->error));
return -1;
}
if (a->filter)
if (a->filter && ! a->filter_eof && ! a->error)
/* We have a filter function and the last time we tried to read we
didn't get an EOF or an error. Try to fill the buffer. */
{
len = a->d.size;
/* Be careful to account for any buffered data. */
len = a->d.size - a->d.len;
if (DBG_IOBUF)
log_debug ("iobuf-%d.%d: underflow: req=%lu\n",
log_debug ("iobuf-%d.%d: underflow: A->FILTER (%lu bytes)\n",
a->no, a->subno, (ulong) len);
rc = a->filter (a->filter_ov, IOBUFCTRL_UNDERFLOW, a->chain,
a->d.buf, &len);
if (len == 0)
/* There is no space for more data. Don't bother calling
A->FILTER. */
rc = 0;
else
rc = a->filter (a->filter_ov, IOBUFCTRL_UNDERFLOW, a->chain,
&a->d.buf[a->d.len], &len);
a->d.len += len;
if (DBG_IOBUF)
{
log_debug ("iobuf-%d.%d: underflow: got=%lu rc=%d\n",
a->no, a->subno, (ulong) len, rc);
log_debug ("iobuf-%d.%d: A->FILTER() returned rc=%d (%s), read %lu bytes\n",
a->no, a->subno,
rc, rc == 0 ? "ok" : rc == -1 ? "EOF" : gpg_strerror (rc),
(ulong) len);
/* if( a->no == 1 ) */
/* log_hexdump (" data:", a->d.buf, len); */
}
if (a->use == IOBUF_INPUT && rc == -1)
{ /* EOF: we can remove the filter */
if (rc == -1)
/* EOF. */
{
size_t dummy_len = 0;
/* and tell the filter to free itself */
/* Tell the filter to free itself */
if ((rc = a->filter (a->filter_ov, IOBUFCTRL_FREE, a->chain,
NULL, &dummy_len)))
log_error ("IOBUFCTRL_FREE failed: %s\n", gpg_strerror (rc));
/* Free everything except for the internal buffer. */
if (a->filter_ov && a->filter_ov_owner)
{
xfree (a->filter_ov);
a->filter_ov = NULL;
}
a->filter = NULL;
xfree (a->filter_ov);
a->filter_ov = NULL;
a->filter = NULL;
a->filter_eof = 1;
if (!len && a->chain)
if (a->d.len == 0 && a->chain)
/* We don't need to keep this filter around at all:
- we got an EOF
- we have no buffered data
- a filter follows this one.
Unlink this filter. */
{
iobuf_t b = a->chain;
if (DBG_IOBUF)
log_debug ("iobuf-%d.%d: pop in underflow (!len)\n",
log_debug ("iobuf-%d.%d: pop in underflow (nothing buffered, got EOF)\n",
a->no, a->subno);
xfree (a->d.buf);
xfree (a->real_fname);
memcpy (a, b, sizeof *a);
xfree (b);
print_chain (a);
return -1;
}
else if (a->d.len == 0)
/* We can't unlink this filter (it is the only one in the
pipeline), but we can immediately return EOF. */
return -1;
}
else if (rc)
a->error = rc;
if (!len)
/* Record the error. */
{
if (DBG_IOBUF)
log_debug ("iobuf-%d.%d: underflow: eof\n", a->no, a->subno);
return -1;
a->error = rc;
if (a->d.len == 0)
/* There is no buffered data. Immediately return EOF. */
return -1;
}
a->d.len = len;
a->d.start = 0;
return a->d.buf[a->d.start++];
}
else
{
if (DBG_IOBUF)
log_debug ("iobuf-%d.%d: underflow: eof (no filter)\n",
a->no, a->subno);
return -1; /* no filter; return EOF */
}
assert (a->d.start <= a->d.len);
if (a->d.start < a->d.len)
return a->d.buf[a->d.start++];
/* EOF. */
return -1;
}